Modine Manufacturing PDE Installation And Service Manual page 11

Gas-fired unit heater

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Table Of Contents

Table of Contents

6 6 . . F F A A U U L L T T F F I I N N D D I I N N G G G G U U I I D D E E

6 6 . . 1 1 I I f f p p i i l l o o t t d d o o e e s s n n o o t t l l i i g g h h t t : :

P P O O S S S S I I B B L L E E C C A A U U S S E E S S A A N N D D R R E E M M E E D D I I E E S S

a. Check that manual gas control knob on combination gas

control is in the pilot position.

b. Bleed air from the pilot line (take special care when bleeding

propane units).

c. If pilot splutters, check pilot line for condensate or other

obstruction.

d. If pilot flame is feeble or short, check orifice for cleanliness.

Replace if necessary. See page 7 for pilot flame adjustment.

e. If the above steps do not correct the condition, consult your

qualified installation and service contractor or gas supplier.

6 6 . . 2 2 I I f f p p i i l l o o t t d d o o e e s s n n o o t t r r e e m m a a i i n n a a l l i i g g h h t t : :

P P O O S S S S I I B B L L E E C C A A U U S S E E S S A A N N D D R R E E M M E E D D I I E E S S

a. Check inlet pressure with all units operating, making certain

that there is correct pressure.

b. Check pipe size to unit.

c. Be sure all pilot connections are tight.

d. Check for excessive draughts.

e. Check for blocked pilot orifice or pilot line.

f. Check for leaks around pilot fittings. If leaks cause flame

impingement on thermocouple lead, thermocouple may

become inoperative.

g. Ensure thermocouple and interrupter connections are both

clean and tight at the gas valve.

h. Ensure all connections between overheat thermostat and

thermocouple are clean and secure.

i. Check the overheat thermostat for correct operation. See page

j. If the above steps do not correct the condition, consult your

qualified installation and service contractor or gas supplier.

6 6 . . 3 3 E E f f f f e e c c t t o o f f p p i i l l o o t t o o p p e e r r a a t t i i o o n n o o n n s s a a f f e e t t y y c c o o n n t t r r o o l l s s : :

P P O O S S S S I I B B L L E E C C A A U U S S E E S S A A N N D D R R E E M M E E D D I I E E S S

a. A short pilot flame may cause poor ignition or reduce heat on

thermocouple to the point where the automatic controls

become inoperative, thereby shutting off gas supply to main

burners. This may result from a blocked injector.

b. Check electrical connection from the thermocouple interrupter

to the safety valve to ensure good electrical contact. Also

check location of pilot flame in relation to thermocouple

element.

6 6 . . 4 4 I I f f m m a a i i n n b b u u r r n n e e r r s s d d o o n n o o t t l l i i g g h h t t : :

P P O O S S S S I I B B L L E E C C A A U U S S E E S S A A N N D D R R E E M M E E D D I I E E S S

a. Check power to appliance is turned on.

b. Check room thermostat and time switch (if fitted) are calling

for heat.

c. Check that knob on combination gas control is in ON position.

d. Be sure pilot is lit, correctly positioned and strong enough to

ignite burner ports.

e. Check wiring (electrical power supply) to combination gas

control.

f. If the above steps do not correct the condition, consult your

qualified installation and service contractor or gas supplier.

T T A A B B L L E E 3 3

S S P P A A R R E E P P A A R R T T S S L L I I S S T T

D D e e s s c c r r i i p p t t i i o o n n

C C o o m m b b i i n n a a t t i i o o n n g g a a s s v v a a l l v v e e

Models 30 - 250

Models 300 - 400

C C o o m m p p l l e e t t e e f f a a n n & & m m o o t t o o r r

100

125

150

175

200

250

300

350

400

F F a a n n m m o o t t o o r r

100

125

150

175

200

250

300

350

400

F F a a n n g g u u a a r r d d

100

125

150

175

200

250

300

350

400

F F a a n n

100

125

150

175

200

250

300

350

400

L L i i m m i i t t t t h h e e r r m m o o s s t t a a t t

D D e e l l a a y y t t i i m m e e r r

T T h h e e r r m m o o c c o o u u p p l l e e

i i n n t t e e r r r r u u p p t t e e r r

W W h h e e n n s s e e r r v v i i c c i i n n g g , , r r e e p p a a i i r r i i n n g g o o r r r r e e p p l l a a c c i i n n g g p p a a r r t t s s o o n n t t h h e e s s e e u u n n i i t t s s

a a l l w w a a y y s s g g i i v v e e t t h h e e c c o o m m p p l l e e t t e e M M o o d d e e l l N N u u m m b b e e r r a a n n d d S S e e r r i i a a l l N N u u m m b b e e r r

f f r r o o m m a a p p p p l l i i a a n n c c e e d d a a t t a a p p l l a a t t e e . .

N N u u m m b b e e r r p p e e r r u u n n i i t t

M M o o d d i i n n e e p p a a r r t t

n n u u m m b b e e r r

5H75043B

5H75116B

HTPMG2304101

HTPMG31541xx

HTPMG3154107

HTPMG3504118

HTPMG3504106

HTPMG4104135